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The width of Herschel filaments varies with distance
No full textContext. Filamentary structures in nearby molecular clouds have been found to exhibit a characteristic width of 0.1 pc, as observed in dust emission. Understanding the origin of this universal width has become a topic of central importance in the study of molecular cloud structure and the early stages of star formation.Aims. We investigate how the recovered widths of filaments depend on distance from the observer, by using previously published results from the Herschel Gould Belt Survey.Methods. We obtain updated estimates on the distances to nearby molecular clouds observed with Herschel, by using recent results based on 3D dust extinction mapping and Gaia. We examine the widths of filaments from individual clouds separately, as opposed to treating them as a single population. We use these per-cloud filament widths to search for signs of variation amongst the clouds of the previously published study.Results. We find a significant dependence of the mean per-cloud filament width with distance. The distribution of mean filament widths for nearby clouds is incompatible with that of farther away clouds. The mean per-cloud widths scale with distance approximately as 4–5 times the beam size. We examine the effects of resolution by performing a convergence study of a filament profile in the Herschel image of the Taurus Molecular Cloud. We find that resolution can severely affect the shapes of radial profiles over the observed range of distances.Conclusions. We conclude that the data are inconsistent with 0.1 pc being the universal characteristic width of filaments
Is the molecular KS relationship universal down to low metallicities?
No full textIn recent years it has been speculated that in extreme low metallicity galactic environments, stars form in regions that lack H2. In this paper we investigate how changing the metallicity and UV-field strength of a galaxy affects the star formation within, and the molecular gas Kennicutt-Schmidt relation. Using extremely high resolution arepo simulations of isolated dwarf galaxies, we independently vary the metallicity and UV-field to between 1% and 10% solar neighbourhood values. We include a non-equilibrium, time-dependant chemical network to model the molecular composition of the ISM, and include the effects of gas shielding from an ambient UV field. Crucially our simulations directly model the gravitational collapse of gas into star-forming clumps and cores and their subsequent accretion using sink particles. In this first publication we find that reducing the metallicity and UV-field by a factor of 10 has no effect on star formation, and minimal effect on the cold, dense star forming gas. The cold gas depletion times are almost an order of magnitude longer than the molecular gas depletion time due to the presence of star formation in HI dominated cold gas. We study the H2 KennicuttSchmidt relationship that arises naturally within the simulations and find a near linear power law index of Ν = 1.09 ± 0.014 in our fiducial 10% solar metallicity model. As the metallicityand UV-field are reduced this becomes moderately steeper, with a slope of Ν =1.24 ± 0.022 for our 1% solar metallicity and 1% solar UV field model
Influence of emulsified plant oil composition on growth and biopolymer production of Cupriavidus necator DSM 545
No full textCupriavidus necator DSM 545 was cultivated on a range of crude and emulsified plant oils (olive, rapeseed, sesame seed, spent coffee grounds (SCGs) and sunflower) of varying fatty acid (FA) composition to assess their influence on the organism’s growth and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] biopolymer production. Initially five different surfactants (gum arabic, dimethyl sulfoxide (DSMO), Tween 80, Triton X-100, and sodium dodecyl sulfate) were screened for their influence on cell growth and ability to form stable oil-in-water emulsions. The highest total biomass (11.3 ± 0.2 g L−1) and P(3HB-co-3HV) (10.0 ± 0.6 g L−1) concentrations were achieved with SCGs oil emulsified with DMSO. At 88.9 ± 5.2 %, the corresponding polymer fraction of the total biomass is among the highest values reported in the literature. During the initial growth phase (0 – 24 h), the organism consumed all fatty acids in broadly the same proportion, but preference was then displayed in the subsequent P(3HB-co-3HV) production phase (24 – 120 h) for saturated FAs (particularly palmitic acid) over unsaturated FAs. SCG oil was an ideal substrate in comparison to the other plant oils due to its high acid value (17.9 ± 0.1 mgKOH goil−1) and palmitic acid content (31.4 ± 0.5 %, w/w). Emulsifying the plant oil cultures initially increased substrate bioavailability, but the influence diminished as the fermentations progressed. Overall, the use of SCGs as a feedstock for PHA production will help reduce the manufacturing costs of the biopolymer and generate a valorisation strategy for an otherwise highly unutilised resource.KeywordsCupriavidus necator; Polyhydroxyalkanoates; Plant oils; Fatty acids; Surfactants; Waste valorisation<br/
Non-restrictive interventions to reduce self-harm amongst children in mental health inpatient settings: Systematic review and narrative synthesis
No full textRates of self-harm amongst children appear to be increasing. This presents challenges for practitioners responsible for maintaining the safety of children admitted to mental health inpatient settings. Policy guidelines recommend that practitioners should aim to avoid the use of restrictive practices for children. It is currently unclear, however, what evidence-based alternatives to restrictive practices are available. We aimed to identify what non-restrictive interventions have been proposed to reduce self-harm amongst children in mental health inpatient settings and to evaluate the evidence supporting their use in clinical practice. A systematic search of five databases (CINAHL, Embase, Ovid MEDLINE, APA Psycinfo, and Cochrane) was conducted to identify articles reporting on non-restrictive interventions aimed at reducing self-harm amongst children in mental health inpatient settings. Articles were quality assessed and relevant data were extracted and synthesised using narrative synthesis. Searches identified relatively few relevant articles (n=7) and these were generally of low methodological quality. The underlying theoretical assumptions and putative mechanisms of change for the interventions described were often unclear. Despite concerns about the rates of self-harm amongst children in mental health inpatient settings, there is a lack of high-quality research to inform clinical practice. There is an urgent need to develop effective and non-restrictive interventions aimed at reducing self-harm for children using inpatient mental health services. Intervention development should be theoretically informed and be conducted in collaboration with people who have lived experience of this issue
Effect of graphene oxide in the formation of polymeric asymmetric membranes via phase inversion
No full textMembrane morphology of integrally skinned asymmetric membranes made by phase 15 inversion can be tailored by precise control of the thermodynamic properties of the casting 16 solution. In this work, the morphology of polyethersulfone (PES) and polyvinylidene 17 fluoride (PVDF) membranes containing graphene oxide (GO) and their phase separation 18 behavior have been studied. The Flory-Huggins theory and the Hansen solubility 19 parameters have been used to construct theoretical binodal lines for ternary and 20 quaternary systems, which have been validated by conducting cloud titration experiments. 21 Moreover, the effect of different solvents on the morphology of PES membranes is 22 discussed through the thermodynamic and kinetic properties of the casting solutions. 23 Nontoxic solvents dimethyl sulfoxide (DMSO) and dihydrolevoglucosenone (CyreneTM) 24 induce PES/GO membranes with finger-like pores and cellular voids, respectively. The 25 addition of GO in the PES and the PVDF casting solutions increases their thermodynamic 26 instability, leading to thinner selective top layers and higher porosities, up to a point 27 where the high viscosity of the GO-containing solutions hinders the solvent-nonsolvent 28 demixing. The highest porosity and pure water flux (PWF) occurs at 0.1 wt% GO for 29 PES/GO/DMSO and at a loading of 0.3 wt% GO for systems PES/GO/Cyrene and 30 PVDF/GO
Deoxyribonucleic Acid Polymer Nanoparticle Hydrogels
No full textPolymer nanoparticle hydrogels made of deoxyribonucleic acid and silica have been prepared and shown to display shear thinning and self-healing properties, sustained release of cargo and enzymatic degradation
The reporting quality of split-mouth trials in orthodontics according to CONSORT guidelines: 2015 – 2019
No full textAlpha entrainment drives pain relief using visual stimulation in a sample of chronic pain patients. A proof-of-concept controlled study.
No full textOne-third of the population in the UK and worldwide struggle with chronic pain. Entraining brain alpha activity through non-invasive visual stimulation has been shown to reduce experimental pain in healthy volunteers. Neural oscillations entrainment offers a potential non-invasive and non-pharmacological intervention for patients with chronic pain, which can be delivered in the home setting and has the potential to reduce use of medications. However, evidence supporting its use in patients with chronic pain is lacking. This study explores whether a) alpha entrainment increase alpha power in patients and b) whether this increase in alpha correlates with analgesia. 28 patients with chronic pain sat in a comfortable position and underwent 4-minute visual stimulation using customised goggles at 10 Hz (alpha) and 7 Hz (control) frequency blocks in a randomised cross-over design. 64-channel Electroencephalography (EEG) and 11-point Numeric Rating Scale (NRS) pain intensity and pain unpleasantness scores were recorded before and after stimulation. EEG analysis revealed frontal alpha power was significantly higher when stimulating at 10 Hz when compared to 7 Hz. There was a significant positive correlation between increased frontal alpha and reduction in pain intensity (r=0.33, p<0.05) and pain unpleasantness (r=0.40, p<0.05) in the 10 Hz block. This study provides the first proof of concept that changes in alpha power resulting from entrainment correlate with an analgesic response in patients with chronic pain. Further studies are warranted to investigate dose-response parameters and equivalence to analgesia provided by medications
Using the ash of common water reeds as a silica source for producing high purity ZSM-5 zeolite microspheres
No full textUtilizing of ash extracted from Iraqi common water reeds as an inexpensive effective silica source in the preparation of ZSM-5 zeolite was investigated for the first time in the present work. This study was conducted using a hydrothermal treatment at autogenous pressure. The molar content of silica (17.84-26.76), sodium oxide (1.71-2.4), water (76.92-304.6), organic template (0.55-2.73), organic solvent (23.46-140.76), and synthesis conditions (crystallization time (24-72 h) and temperature (130-180 ⁰C)) were investigated to obtain high purity ZSM-5 zeolite microspheres. The zeolite samples were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Analysis by X-Ray (EDAX), N2 adsorption/desorption isotherms, Thermogravimetric Analyzer (TGA), and Fourier transform infrared spectroscopy (FTIR). XRD pattern of all synthesized samples was compared to XRD pattern of the commercial ZSM-5 zeolite. This work allows using locally available solid waste resulted from a dry natural plant as an inexpensive silica source without using an external source of silica. Also, this is the first report of the direct synthesis of a high purity ZSM-5 zeolite microspheres from common water reeds ash containing highly reactive silica. A gel composition of 2Na2O: 26.76SiO2: Al2O3: 2.73TPAOH: 23.46EtOH: 304.6H2O gave an outstanding final product of ZSM-5 zeolite microspheres at 180 ⁰C and 27 h. This high crystallinity ZSM-5 zeolite porous microspheres possess Si/Al ratio of 17, a crystal size of 61.419 nm, BET surface area of 277.482 m2/g, a total pore volume of 0.1659 cm3/g, micropore volume of 0.1131 cm3/g, pore width of 5.28 nm, and hierarchical factor of 0.14
Blood Prestin Levels in Normal Hearing and in Sensorineural Hearing Loss: a Scoping Review
No full textRecently it has been hypothesized that blood prestin concentration levels may reflect cochlear damage and thus serve as an easily measurable, early sensorineural hearing loss biomarker. This is a scoping review aiming to identify and critically appraise current evidence on prestin blood levels and their temporal variation in rodents and humans with normal hearing and with sensorineural hearing loss. This study was designed and held according to PRISMA Extension for Scoping Reviews (PRISMAScR) guidelines. With no limitation with regards to study type, animal and human studies focusing on prestin blood levels in normal hearing and in sensorineural hearing loss were sought in major databases such as Medline, Central. Scopus, PROSPERO and Clinicaltrials.gov. Results have been then hand-searched. A data charting form was developed including the parameters of interest. Seven studies focusing on measuring prestin blood levels by means of ELISA in rodents and human subjects with normal hearing and noise-induced, drug-induced, or idiopathic sudden hearing loss were found eligible and were included in the analysis. According to these proof-of concept studies, prestin can be detected in the circulation of subjects with no hearing loss, however normal ranges remain unclear. After cochlear damage, blood prestin levels seem to initially rise and then return to near or below baseline. The degree of their change relates with subjects’ degree of hearing loss, damaged cochlear region and recovery. Prestin blood levels and their temporal variation seem to correlate with cochlear damage, however methodological weaknesses, such as small sample size, lack of detailed phenotyping, insufficient exclusion of confounding factors and short follow-up do not allow for robust conclusions. To conclude, current findings support the value of studying blood prestin levels in normal hearing and hearing loss, and highlight a need for larger scale longitudinal research